This invention relates to the removal of defective semiconductor chips from hybrid integrated circuits.
As should be expected, present production of hybrid integrated circuits, which combine thin film elements and integrated circuit semiconductor chips on a single ceramic substrate, result in less than 100% yield. Since many such circuits are quite complex and expensive, it is desirable whenever feasible to repair a defective circuit rather than discard it. Such repair techniques typically involve removal of a defective integrated circuit semiconductor chip from the rest of the circuit, including removal of the protective encapsulant typically formed over the chip. This removal is usually effected by selectively coring and peeling the encapsulant followed by mechanically scraping off the chip. While such a procedure is adequate, it is relatively slow for use in a mass production situation. In addition, there is some possibility that such removal will cause damage to areas of the circuit other than those to be repaired.
It is therefore a primary object of the invention to provide a means for removal of chips and encapsulant from a hybrid circuit which is fast, reproducible, easily automated and will not cause damage to the repair site or adjacent portions of the circuit.